The present invention relates to an apparatus for indicating an optimum time to shift a manual transmission installed in a vehicle, and more particularly to the apparatus for indicating an optimum time to shift a manual transmission working in conjunction with an electronically controlled fuel injection type engine.
A goal of the motorized vehicle industry is to reduce the amount of fuel consumed in the vehicles it now produces to reduce the rate at which world-wide oil reserves are being depleted.
In general, the amount of fuel consumed by a vehicle varies according to engine performance and the operator's driving technique. If an operator has little knowledge of when a manual transmission should be shifted, an apparatus which indicates the optimum time to shift gives the uninformed operator the proper cue for when to shift, thereby decreasing the fuel consumption rate.
Known devices have attempted to obviate the aforementioned problems by monitoring the vacuum created in an air intake pipe of an engine thereby indicating the load upon an engine and others have indicated how far a vehicle would travel at the present fuel consumption rate, i.e. Km/1 or MPG.
Neither of the aforementioned devices actually instructs the operator on how to actually operate the car, hence not achieving all potential advantages of knowing how to reduce the fuel consumption rate.
In view of the aforementioned background, an apparatus that actually instructs the operator of a vehicle when to shift the transmission, in accordance with engine RPM and the intake vacuum, has been devised. Additionally, an apparatus having a memory device memorizes optimum shifting times in conjunction with various operating parameters such as engine RPM, vehicle speed and the load upon the engine, and compares them to actual vehicle operating conditions. When the actual conditions vary from the memorized conditions, the apparatus recommends the optimum gear which should be used.
According to the previous design of a similar apparatus, the optimum time to shift gears was not correctly indicated until the temperature of the engine coolant reached a certain elevated value. Therefore, the goal of reducing fuel consumption in the warming-up stages of the engine was not achieved.